TEMPERATURE DEPENDENCE OF HOMOGENEOUS ANATASE-PHASED TiO2 FILMS CHARACTERIZATION AND GAS-SENSING BEHAVIORS
Abstract
Anatase-phased TiO2 films were prepared at different temperatures (350, 400, 450 and 500∘C) using automated nebulizer spray pyrolysis (ANSP) method. The structural study (XRD) revealed the amorphous nature at 350∘C and remaining samples (400, 450 and 500∘C) show the tetragonal structure with 2θ∘=25.78, 38.43, 48.49 and 55.54 corresponding to (101), (004), (200) and (105) reflected planes and it is well fitted with standard data. The compositional XPS analysis confirmed the core level primary element of Ti 2p, O 1s and valance band (VB) of Ti 3p, Ti 3s, O 2s peaks in the prepared samples. The 3D optical profilometer has shown that the thickness of the prepared films was decreased by increase in temperature. The AFM study exhibited average roughnesses (Ra) of the prepared films such as 0.058, 0.147, 0.176 and 0.194nm, respectively. The surface morphological study of FESEM has shown the cracked uneven distributed nature (350∘C) turn into evenly distributed closed packed agglomerated particles by the influence of temperature. The oscillating nature of transmittance (%) with redshift of the sharp absorption edge was observed in UV–Vis–NIR spectrophotometer and found the bandgap value about 3.58eV to 3.33eV through Tauc’s relation. The gas-sensing behavior has shown better response to C2H6O reducing gas at 300∘C operating temperature with 150 ppm gas concentration.
